A variety of electronic devices may utilize a rechargeable battery. Such electronic devices may include laptop computers, cell phones, personal digital assistants, power tools, etc. A variety of rechargeable batteries may be utilized in such devices, e.g., lithium-ion, nickel-cadmium, and nickel-metal hydride batteries. Some rechargeable batteries, e.g., lithium-ion batteries, may become hazardous under certain conditions including over voltage conditions. Hence, a variety of battery protection circuits may be utilized in battery packs of such rechargeable batteries.
In some instances, a secondary battery protection circuit may be utilized in addition to a primary battery protection circuit. The secondary battery protection circuit may provide an output to a fuse element to permanently disable the fuse element in response to a sustained over voltage condition. However, such secondary protection circuit does not protect against short over voltage spikes. In addition, the fuse element is not capable of moving between conductive and non-conductive states since once the fuse element enters a non-conductive state, it cannot move back to a conductive state (i.e., once tripped the fuse element would need to be replaced).
Furthermore, conventional secondary battery pack protection circuits may not detect a relatively high voltage strike occurred at a relatively short time period.